Vanadium‐Incorporated Manganese Sulfide Secondary Particles With Nano‐Nodular Surfaces for Pseudocapacitive Energy Storage

Transition metal sulfides (TMSs) show promise as electrode materials for pseudocapacitors (PCs). However, their practical application is obstructed by low intrinsic conductivity and poor rate capability. Vanadium‐incorporated hierarchical manganese sulfide (MnS) secondary particles were synthesized through a synergy strategy between vanadium incorporation and L‐cysteine surface functionalization, enhancing PC performance. This dual modification approach induced significant physicochemical changes, including distinct morphological transformations and altered crystal growth. As a result, the optimized growth‐controlled vanadium‐incorporated MnS (G‐VMnS) electrode demonstrated improved electrochemical performance compared to bare MnS and growth‐controlled MnS (G‐MnS). It exhibited a high specific capacitance of 271.0 F/g at 10 mV/s, along with significantly lower charge transfer resistance and more efficient ion diffusion. This enhancement is attributed to the synergistic effects of vanadium incorporation and L‐cysteine surface functionalization that generate additional redox‐active sites and change the surface chemical bonding states of MnS. This study highlights that combining surface modification and heteroatom incorporation is highly effective for developing advanced electrode materials for supercapacitors (SCs).